Mechanisms for coupling vehicles, structural elements or machinery for that matter are many and varied in design. Usually the mechanical coaction called for represents an end product which is commensurate with the evolution of a system. As an example, the technological advancements in undersea technology have fostered a whole new breed of sophisticated undersea craft. Some of the latest developments in this field are the family of unmanned undersea vehicles usually controlled from the surface. Unmanned vehicles have a number of features making them particularly acceptable when hazardous conditions are expected. A recent development has extended the capabilities of existing tethered vehicles. The system is generally referred to as the remote unmanned work system (RUWS). RUWS is capable of performing underwater search, inspection, work, and object recovery tasks at great ocean depths and is provided with acoustic and visual sensing and location devices. This system deploys an interconnected secondary vehicle and a tethered primary vehicle by a relatively heavy cable which also transmits electric power lines and command and control lines etc. The primary vehicle disconnects from the secondary vehicle at or near the work site at a predetermined depth. It is tethered to the secondary vehicle via a lighter weight cable which also feeds power and control signals. The tethered vehicle carries the tools necessary to perform a task and support equipment such as lights, cameras, etc., while the secondary vehicle acts as a platform for power conversion equipment, signal processing circuitry, etc. The advantages of such an arrangement are obvious. Once the task is completed the primary vehicle becomes connected to the secondary vehicle and the entire package is retrieved by a surface support vessel via the heavy cable. Heretofore, problems have arisen because of the coupling between the two vehicles. If the two vehicles are not capable of joining and separating reliably, there is a possibility of damage and consequent mission ineffectiveness. A continuing need exists in the state-of-the-art for a mechanism which ensures reliable joining and separation of a pair of tethered vehicles remotely from a support ship.